Brendan Rodgers was a spectator at Manchester City’s English Premier League clash with Huddersfield on Sunday.
Celtic have had a fair number of loan stars from the Sky Blues, including John Guidetti, Patrick Roberts and Daniel Arzani.
While it’s unlikely he was eyeing up any of the multi-million pound talent on show in the City first team, there are a number of players at the Etihad who Rodgers may have had his eye on. Here, we look at who they are...
The 21-year-old Philippe Sandler, who joined Manchester City from PEC Zwolle last month, is one possibility.
The 6ft 2in central defender played 30 times for the Dutch side, and joined the Blauwvingers after coming through the Ajax academy.
The Netherlands Under-20 international agreed to swap Zwolle for Manchester in March, with the move going through in the close season.
Sandler, who can also play the holding midfield role, scored his first senior goal in a Dutch Cup match against Kozakken Boys in 2017 and helped Zwolle to ninth place in the 2017/18 Eredivisie.
Predominantly right-footed, Sandler has been likened to his countryman and former Celtic defender Virgil van Dijk.
Rangers have also been linked with a move for the defender, although it is understood City are keen for Sandler to get plenty of game time if they sanction a loan move.
The versatile Oleksandr Zinchenko, who can operate as an attacking midfielder or at wingback, is a Ukrainian international with 17 caps including appearances at Euro 2016.
He spent his youth career with local side Karpatiya Radomyshl before spells with Monolit Illichivsk and Shakhtar Donetsk.
Zinchenko’s senior career began with FC Ufa. He played 33 times for the Bashkortostan outfit over two seasons, scoring twice, before joining City in July 2016 for a fee in the region of £1.7 million.
The 21-year-old was loaned out to Dutch side PSV Eindhoven for the 2016/17 season, making a combined 24 appearances for the senior team and the club’s second string XI, Jong PSV.
Last season, the Ukrainian played 14 times for Pep Guardiola’s side, deputising after injuries to Benjamin Mendy and Fabian Delph.
Reports in Spain suggest that Zinchenko is also a target for Real Betis and Girona, who signed Patrick Roberts on loan from City last week.
A £16 million permanent deal was agreed with Wolves earlier this summer but Zinchenko knocked back the move after refusing to give up on his future with the Citizens.
Whether or not Celtic’s interest is genuine is unclear, but the Hoops are on the lookout for midfield reinforcements having missed out on John McGinn to Aston Villa.
Admittedly, any return to Celtic for Jason Denayer looks dead in the water, amid reports the Belgian defender has already been training with French side Lyon ahead of a proposed switch.
A journalist for L’Equipe reported that the former Galatasaray loanee trained with OL on Monday morning despite reports last week that a second loan spell with the Hoops hadn’t been ruled out.
Denayer starred for the Hoops during the 2014/15 season, picking up the Young Player of the Year award, and despite attempts to bring him back for a second stint, the defender went to Turkey, followed by Sunderland, and then back to Istanbul, where he impressed again last season. However, it looks as though Denayer’s move to Lyon is all but done.